package com.stack.common.utils;

import com.stack.common.exception.BusinessException;

import java.io.*;
import java.net.HttpURLConnection;
import java.net.URL;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * @Author : kxw
 * @Date : 2021/5/21 10:48 上午
 */
public class DownloadUtils {

    /**
     * 从网络Url中下载文件
     * @param urlStr
     * @param fileName
     * @param savePath
     * @throws IOException
     */
    public static void downLoadFromUrl(String urlStr,String fileName,String savePath) throws IOException {
        URL url = new URL(urlStr);
        HttpURLConnection conn = (HttpURLConnection)url.openConnection();
        //设置超时间为3秒
        conn.setConnectTimeout(3*1000);
        //防止屏蔽程序抓取而返回403错误
        conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");

        //得到输入流
        InputStream inputStream = conn.getInputStream();
        //获取自己数组
        byte[] getData = readInputStream(inputStream);

        //文件保存位置
        File saveDir = new File(savePath);
        if(!saveDir.exists()){
            saveDir.mkdir();
        }
        File file = new File(saveDir+File.separator+fileName);
        FileOutputStream fos = new FileOutputStream(file);
        fos.write(getData);
        if(fos!=null){
            fos.close();
        }
        if(inputStream!=null){
            inputStream.close();
        }
    }


    /**
     * 从网络Url中下载文件
     * @param
     * @param fileName
     * @param savePath
     * @throws IOException
     */
    public static void downLoadFromBytes(byte[] bytes,String fileName,String savePath) throws IOException {

        //文件保存位置
        File saveDir = new File(savePath);
        if(!saveDir.exists()){
            saveDir.mkdir();
        }
        File file = new File(saveDir+File.separator+fileName);
        FileOutputStream fos = null;
        try {
            fos = new FileOutputStream(file);
            fos.write(bytes);
        } catch (Exception e) {
            throw new BusinessException(e.getMessage());
        } finally {
            if(fos!=null){
                fos.close();
            }
        }
    }


    /**
     * 从网络Url中下载文件
     * @param urlStr
     * @throws IOException
     */
    public static InputStream getInputStreamFromUrl(String urlStr) throws IOException {
        URL url = new URL(urlStr);
        HttpURLConnection conn = (HttpURLConnection)url.openConnection();
        //设置超时间为3秒
        conn.setConnectTimeout(3*1000);
        //防止屏蔽程序抓取而返回403错误
        conn.setRequestProperty("User-Agent", "Mozilla/4.0 (compatible; MSIE 5.0; Windows NT; DigExt)");

        //得到输入流
        InputStream inputStream = conn.getInputStream();
        return inputStream;
    }


    /**
     * 从输入流中获取字节数组
     * @param inputStream
     * @return
     * @throws IOException
     */
    public static  byte[] readInputStream(InputStream inputStream) throws IOException {
        byte[] buffer = new byte[1024];
        int len = 0;
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        while((len = inputStream.read(buffer)) != -1) {
            bos.write(buffer, 0, len);
        }
        bos.close();
        return bos.toByteArray();
    }

    /**
     * 从网络Url中下载文件,以byte数组方式返回
     * @param urlStr
     * @throws IOException
     */
    public static byte[] getByteFileByUrl(String urlStr) throws IOException {
        InputStream inputStream = getInputStreamFromUrl(urlStr);
        byte[] byteFile = readInputStream(inputStream);
        if (inputStream != null){
            inputStream.close();
        }
        return byteFile;
    }

    public static String getFileNameFromURL(String urlString) {
        try {
            URL url = new URL(urlString);

            // 获取URL中的路径部分
            String path = url.getPath();

            // 使用正则表达式匹配路径中的文件名
            Pattern pattern = Pattern.compile(".*/(.*?)$");
            Matcher matcher = pattern.matcher(path);

            if (matcher.find()) {
                return matcher.group(1);
            }
        } catch (Exception e) {
            e.printStackTrace();
        }

        return null;
    }

    public static void main(String[] args) {
        try{
            downLoadFromUrl("https://txcdn2.emodor.com/file/385436/202105201628410.docx", "合同模板文件.docx","/Users/apple/Documents/");
        } catch (Exception e) {
            System.out.println("下载失败");
        }
    }
}
